Interesting you say that. What we call a vacuum pump only has to be able to move a cylinder against a small pressure of 15 pounds per square inch.
Move a cylinder?
Explain what you mean by move a cylinder?
Oops. I meant move a piston. A basic pump is just a piston going up and down in a cylinder with some valves.
Highly effective vacuum pumps do NOT require strength.
So all evacuation pumps are the same strength then; is this what you're saying?
No. Some pumps are more solidly built than others and some can pump out more air per second. However, all pumps are only working with a very small pressure difference if they are expelling air into atmospheric pressure and there is no particular strength needed to do that.
The fact you say a strong pump will break the glass STRONGLY suggests there is something you do not understand. Strong or weak the pumps are only working against the same small pressure difference between one atmosphere and whatever the pump can create. Providing the glass can comfortably handle the small pressure difference it is not going to break because a low pressure difference of only 15 pounds per square inch is suddenly created.
What they require is the ability SOMEHOW to gain access to the available material where an ordinary pump has ZERO ability to attract material to the vacuum pump.
Gain ACCESS to the available material?
if the remaining particles of air are moving around in the glass container, or the tube that goes to the pump, the moving piston of an ordinary pump has no ability get hold of them. All the piston can do is expel particles that are already in the cylinder.
Vacuum pumps do not suck. Instead the material finds its own way into the pump - or does not.
Tell me how it finds its way into the pump.
The best explanation we have for gas behaviour is the kinetic theory of gases which you will have heard of. The gas particles are in rapid movement unless the temperature is reduced to absolute zero. Gases move from one part of a container to another by diffusion.
So before particles can be removed from the cylinder they have to have travelled to the cylinder via their own random movement and remain there before the valve closes.
The ordinary vacuum pump has no ability to suck on the air or cause it to change direction or do anything at all. The air does its own thing. The ordinary pump does its thing.
And so if you take a piece of delicate glassware and it is comfortably capable of withstanding a vacuum, which is a small pressure difference between low pressure and one atmosphere, it does not matter what pump you connect it to, none of the pumps have any particular ability to create a force which can damage the glass, because the greatest force they can create is only a small 15 pounds per square inch.